CN112185268B - image display device - Google Patents

Abstract

An image display element according to an aspect includes: the light emitting device includes a driving circuit board including a driving circuit for supplying current to the micro light emitting element and emitting light, the micro light emitting element, a micro lens in contact with a light emitting surface of the micro light emitting element, and a partition wall disposed around the micro lens in a direction parallel to the light emitting surface, a side surface of the partition wall facing the micro lens being a reflecting surface inclined so as to be opened with respect to a light emitting direction and reflecting light.

Description

image display device

technical field

The invention relates to a picture display element comprising a plurality of microluminescence elements.

Background technique

There has been proposed an image display device in which a plurality of micro light-emitting elements constituting pixels are arranged on a driving circuit substrate. For example, in the technique disclosed in Japanese Patent Application Laid-Open No. 2002-141492, a driver circuit is formed on a silicon substrate, and a tiny light emitting diode (LED: light emitting diode) array that emits ultraviolet light is arranged on the driver circuit. In addition, in the above-mentioned technologies, there is disclosed a small image display element that displays a color image by providing a wavelength conversion layer that converts ultraviolet light into visible light of red, green, and blue on a light emitting diode array.

This type of image display device has high brightness and high durability despite its small size, so it is expected to be used as an image for display devices such as glasses-like devices and head-up displays (HUD: Head-Up Display). Display components. As a method of manufacturing such an image display element, since the material of the driving circuit substrate and the material of the micro-light-emitting element are different, the two are generally formed separately and then bonded together.

However, the structure of the micro-light-emitting element and the image display element disclosed in the above-mentioned Japanese Patent Laid-Open No. 2002-141492 has a problem of low light emission efficiency. The main reason for this is that the light extraction efficiency (light extraction efficiency) indicating the ratio of light generated inside the body of the compound semiconductor to the outside is low. Since the compound semiconductor constituting the micro-light emitting element has a larger refractive index than air or resin, when light enters the interface between the compound semiconductor and the outside, total reflection occurs over a wide range of incident angles. As a result, light is confined inside the micro-light-emitting element, and light extraction efficiency decreases.

In addition, "luminous efficiency" refers to the efficiency with which current or electric power input to a micro-light emitting element is converted into light emitted to the outside. In addition, "light extraction efficiency" refers to the ratio of the light generated in the light emitting layer of the micro light emitting element to the light emitted to the outside of the micro light emitting element.

Since the luminous efficiency is lowered due to the lowering of the light extraction efficiency, problems such as an increase in power consumption or a temperature rise due to heat generation may occur.

In addition, the micro-light emitting element exhibits a light emission distribution close to a Lambertian distribution, and a light emission angle distribution is wide. For this reason, excess light that cannot be effectively utilized in an image display element for a small eyeglass type terminal or a display for mobile is emitted. As a result, power consumption increases to an unnecessary level.

Contents of the invention

One aspect of the present invention is made in view of the above-mentioned problems, and its purpose is to realize an image display capable of improving luminous efficiency by suppressing light leakage to adjacent micro-light-emitting elements and enhancing light output to the front direction of the micro-light-emitting elements element.

In order to solve the above-mentioned problems, an image display element according to an aspect of the present invention is an image display element including a plurality of micro-light emitting elements arranged in an array, including: including supplying current to a plurality of the micro-light-emitting elements to make the micro-light-emitting elements The drive circuit substrate of the drive circuit for the element to emit light, the plurality of micro-light-emitting elements, and the plurality of micro-lenses in contact with the light-emitting surfaces of the plurality of micro-light-emitting elements are arranged in a direction parallel to the light-emitting surface . A plurality of partition walls around the plurality of microlenses, wherein side surfaces of the plurality of partition walls facing the plurality of microlenses are reflective surfaces that are inclined and reflect light in a manner that opens relative to a light emitting direction.

In order to solve the above-mentioned problems, an image display element according to one aspect of the present invention includes a plurality of micro-light-emitting elements arranged in an array, and sequentially stacked: a drive circuit that supplies current to the plurality of micro-light-emitting elements and makes them emit light. a drive circuit substrate, a plurality of the micro-light emitting elements, and a wavelength conversion part that extends the wavelength of the excitation light emitted by the plurality of the micro-light-emitting elements, and the image display element has a A plurality of partition walls around the plurality of wavelength conversion parts in a direction parallel to the light exit surface, the plurality of wavelength conversion parts are formed in a shape including a convex curved surface along the light emission direction, and the plurality of partition walls A side surface facing one of the plurality of wavelength conversion parts is a reflective surface that is inclined so as to be open with respect to a light emitting direction and that reflects light.

According to one aspect of the present invention, by suppressing light leakage to adjacent micro-light-emitting elements and enhancing light output toward the front of the micro-light-emitting elements, the luminous efficiency can be improved.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a pixel region of an image display element according to a first embodiment of the present invention.

2 is a schematic plan view of a pixel region of the image display element according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating the functions of microlenses and partition walls.

FIG. 4 shows simulation results of respective light emission angle distributions with and without microlenses.

5 is a schematic cross-sectional view of a pixel region of an image display element according to a second embodiment of the present invention.

6 is a planar schematic view of a pixel region of an image display element according to a third embodiment of the present invention.

7 is a schematic cross-sectional view of a pixel region of an image display element according to a fourth embodiment of the present invention.

8 is a schematic cross-sectional view of a pixel region of an image display element according to a fifth embodiment of the present invention.

9 is a schematic cross-sectional view of a pixel region of an image display element according to a sixth embodiment of the present invention.

10 is a schematic plan view of a pixel region of an image display element according to a sixth embodiment of the present invention.

11 is a schematic cross-sectional view of a pixel region of an image display element according to a seventh embodiment of the present invention.

12 is a simulation result showing the light emission distribution of the blue micro-light emitting element and the light emission distribution of the red micro light emitting element according to the seventh embodiment of the present invention.

13 is a schematic cross-sectional view of a pixel region of an image display element according to an eighth embodiment of the present invention.

14 is a schematic cross-sectional view of an image display element according to a ninth embodiment of the present invention.

15 is a schematic cross-sectional view of a red micro-luminescence element of an image display element according to a ninth embodiment of the present invention.

16 is a schematic cross-sectional view of a pixel region of an image display element according to a tenth embodiment of the present invention.

17 is a schematic cross-sectional view of a pixel region of an image display element according to an eleventh embodiment of the present invention.

18 is a schematic cross-sectional view of a pixel region of an image display element according to a twelfth embodiment of the present invention.

19 is a schematic cross-sectional view of a pixel region of an image display element according to a thirteenth embodiment of the present invention.

Detailed ways

[first embodiment]

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 4 by taking an image display element 200 including a plurality of micro-light emitting elements 100 as an example. In addition, the image display element 200 includes a plurality of micro light emitting elements 100 and a driving circuit substrate 50 . The driving circuit substrate 50 controls the amount of light emitted from the micro light emitting element 100 by controlling the current supplied to the micro light emitting element 100 included in the pixel region (pixel region) 1 . The micro light emitting element 100 emits light in a direction (light emission direction) on the side opposite to the driving circuit substrate 50 .

In addition, in the description of the structure of the image display element 200, unless otherwise specified, the surface on the side of the light emitting surface (light emitting surface) 101 is referred to as the upper surface (first surface), and the surface on the side opposite to the light emitting surface 101 is referred to as the upper surface (first surface). The surface is called the lower surface (second surface), and the surfaces other than the upper surface and the lower surface are called side surfaces.

(drive circuit board 50)

The driving circuit substrate 50 is composed of a micro light emitting element driving circuit (micro light emitting element driving circuit) that controls the current supplied to each micro light emitting element 100, a row selection circuit that selects each row of pixels arranged in a two-dimensional array, and outputs a light emitting signal. A column signal output circuit to each column, an image processing circuit that calculates a light emission signal based on an input signal, an input/output circuit (driver circuit), and the like are configured.

P drive electrodes 51 (P-drive electrodes) and N drive electrodes 52 (N-drive electrodes) connected to the micro light emitting elements 100 are arranged on the surface of the drive circuit substrate 50 on the side of the connecting surface to which the micro light emitting elements 100 are connected. The drive circuit substrate 50 is generally a silicon substrate (semiconductor substrate) on which LSI (large-scale integration) is formed, a glass substrate on which a thin film transistor (TFT: Thin film transistor) is formed, and the like, and can be manufactured by known techniques, so the The function and structure are not described in detail.

In addition, in FIG. 2 , the shape of the micro-light-emitting element 100 viewed from the upper surface side (light-emitting surface 101 side) is schematically shown as a shape approximately square, but the shape of the micro-light-emitting element 100 is not particularly limited. The shape of the micro-light-emitting element viewed from the upper surface side can adopt various planar shapes such as rectangle, polygon, circle or ellipse, but as the maximum diameter of the maximum length (for example, if it is a circle, it is its diameter, if it is a rectangle) its diagonal) is assumed to be below 60 μm. In addition, it is assumed that the image display element 200 integrates, for example, 3000 or more micro light emitting elements 100 in the pixel region 1 .

(Configuration of image display element 200)

As shown in FIG. 2 , the upper surface of the image display element 200 becomes a pixel region 1 in which a plurality of pixels 5 are arranged in an array. In this embodiment, the image display element 200 is a monochrome display element, and each pixel 5 includes a monochrome micro-light emitting element 100 .

The micro light emitting element 100 includes a compound semiconductor layer 14 (compound semiconductor crystal). For example, an N-side layer (N-side layer) 11 , a light emission layer (light emission layer) 12 , and a P-side layer (P-side layer) 13 are stacked on the compound semiconductor layer 14 . For example, in a micro-light-emitting device that emits light in a wavelength band from ultraviolet to green, the compound semiconductor layer 14 is an AlInGaN-based nitride semiconductor, and in the case of emitting light in a wavelength band from yellow-green to red, the compound semiconductor layer 14 is AlInGaP Department of semiconductors. In addition, when emitting light in a wavelength band from red to infrared, it is an AlGaAs-based or GaAs-based semiconductor.

In this embodiment, only the structure in which the N-side layer 11 is arranged on the light-emitting direction side in the compound semiconductor layer 14 constituting the micro-light-emitting element 100 is described, but the P-side layer 13 may also be arranged on the light-emitting direction side. Generally, multiple layers of N-side layer 11, light-emitting layer 12, and P-side layer 13 are included instead of a single-layer N-side layer 11, light-emitting layer 12, and P-side layer 13, and each layer is configured to be functionally optimized, but due to the The essence of the present invention is not directly related, so the detailed structure of each layer is not described here.

Usually, the light-emitting layer 12 is sandwiched between an N-type layer (N-type layer) and a P-type layer (P-type layer), but there is also an N-type layer, and the P-type layer includes an undoped layer, and includes a The case of layers of dopants of opposite conductivity. Therefore, in this specification, for the two layers sandwiching the light-emitting layer 12, the semiconductor layer on the side containing the N-type layer is referred to as the N-side layer 11, and the semiconductor layer on the side containing the P-type layer is referred to as the P-side layer 11. side layer 13. In addition, in GaN-based compound semiconductors, Si is generally used as an N-type dopant contained in an N-type layer, and Mg is used as a P-type dopant contained in a P-type layer.

Adding a dopant of “opposite conductivity” to the N-side layer 11 or P-side layer 13 corresponds to, for example, adding Si to a part of the P-type layer. That is, the whole is a P-type layer, but a part of the P-type layer contains a low-concentration N-type dopant, and the like.

FIG. 1 shows a schematic cross-sectional view of line A-A shown in FIG. 2 . As shown in FIG. 1 and FIG. 2 , the micro light emitting elements 100 are arranged in a two-dimensional array on the driving circuit substrate 50 . Both the P electrode 23P (P-type electrode) and the N electrode 23N (N-type electrode) of the micro-light-emitting element 100 are formed on the lower surface side of the micro-light-emitting element 100 .

P electrode 23P is connected to P drive electrode 51 formed on drive circuit board 50 . In addition, the N electrode 23N is connected to the N drive electrode 52 formed on the drive circuit board 50 . The current supplied from the drive circuit substrate 50 to the micro light emitting element 100 is transmitted from the P drive electrode 51 to the P side layer 13 via the P electrode 23P. The current passing through the light emitting layer 12 from the P side layer 13 flows from the N side layer 11 to the N driving electrode 52 through the N electrode 23N. Thus, according to the amount of current supplied from the driving circuit substrate 50, the micro light emitting element 100 emits light with a predetermined intensity.

Each micro-light-emitting element 100 is covered by an insulating embedding material 60 and is electrically isolated from each other. When the embedding material 60 is made of a material with high translucency such as transparency, a part of the embedding material 60 may cover the light emitting surface 101 . In this case, since the embedding material 60 has no light-shielding function, in order to suppress light leakage between the micro-light-emitting elements 100, it is preferable to cover the sidewalls of the micro-light-emitting elements 100 with a metal film with low translucency or the like.

On the other hand, in order to suppress light leakage to the adjacent micro light-emitting element 100, when the embedding material 60 is made of a material with low light transmittance such as a light-shielding function by reflecting or absorbing light, the embedding material 60 is not preferable. To cover the light exit surface 101 . Therefore, it is preferable that the height of the light exit surface 101 is substantially equal to the height of the embedding material 60 . According to such a structure, since the embedding material 60 does not interfere with the light emitting surface 101 of the micro-light-emitting element 100 , light emission of the micro-light-emitting element 100 is not hindered.

The microlens 40 has a shape including a flat bottom surface on the side contacting the light exit surface 101 and a curved surface convex in the light emission direction on the outer surface. As such a shape, for example, a spherical surface or an ellipsoidal surface, a so-called hemispherical shape can be exemplified. In addition, in this embodiment, the surface of the microlens 40 is a hemispherical curved surface portion. In addition, the inside of the microlens 40 is filled with materials such as transparent resin with high translucency. That is, the microlens 40 is configured as a convex lens. The bottom surface of the microlens 40 is substantially circular, and its center preferably overlaps with the center of the light exit surface 101 , but may have the same shape as the light exit surface if there is an area limitation. Specifically, the surface of the microlens 40 is a spherical surface, and the center of the spherical surface is preferably located within ±1 μm relative to the center of the light emitting surface 101 .

The bottom surface of the microlens 40 is preferably in contact with the light emitting surface 101 of the micro-light-emitting element 100 , but may also be in contact via a thin transparent film. In addition, it is preferable that the bottom surface of the microlens 40 completely covers the entire light exit surface 101 . The microlens 40 may be formed into a lens shape using the transparent resin, for example, after the transparent resin pattern is formed by photolithography, followed by heat treatment to fluidize the transparent resin. Alternatively, the microlens 40 may be formed by pressing a mold processed into a microlens array shape onto the drive circuit substrate 50 coated with a transparent resin.

A partition wall 34 is provided around the microlens 40 in a direction parallel to the light exit surface 101 . The reflective surface 34S of the partition wall 34 is inclined at an inclination angle θw so as to open in the light emission direction. In this embodiment, the reflective surface 34S is formed around the microlens 40 by forming the partition wall 34 from a material with high reflectivity (for example, a metal material). That is, the microlenses 40 are independently provided for each pixel, and adjacent microlenses 40 are separated from each other by the partition wall 34 .

Examples of high reflectance materials include silver and aluminum. The partition wall 34 may also be formed in a shape in which the side walls are opened and inclined in the light emitting direction by depositing a metal thin film and performing tapered etching using a photolithography technique and a dry etching technique. Alternatively, the partition wall 34 may be formed directly using a metal pattern with inclined side surfaces by a lift-off method. In this embodiment, as shown in FIG. 2 , a constant distance is maintained between the reflective surface 34S and the surface of the microlens 40 . In addition, it is preferable that the reflective surface 34S does not contact the microlens 40 , but the bottom of the partition wall 34 and the bottom of the microlens 40 are allowed to contact to reduce the area of the pixel 5 .

According to the image display element 200 described above, the partition wall 34 is arranged around the microlens 40 . For this reason, light leakage to adjacent micro-light-emitting elements 100 can be suppressed. In addition, according to the image display element 200, the side face of the partition wall 34 facing the microlens 40 is the reflective surface 34S inclined in such a manner as to open in the light emission direction. Therefore, among the light emitted from the microlens 40 , the path of the light traveling toward the partition wall 34 is reflected by the reflective surface 34S and changed to a direction along the front direction (centerline direction) of the micro light emitting element 100 . For this reason, since the light output in the front direction of the micro light emitting element 100 is enhanced, the luminance in the front direction of the micro light emitting element 100 can be improved.

The effect of the microlens 40 and the reflective surface 34S will be described using FIG. 3 and FIG. 4 . Graph 401 of FIG. 4 shows the difference in the light emission distribution of light emitted from the micro-light emitting element 100 depending on the presence or absence of the microlens 40 (shown after integrating the light intensity with respect to the direction towards the azimuthal angle).

As shown in FIG. 3 , the light emission angle (Emission angle) is an angle relative to the centerline of the microlens 40 . In addition, since the light emission distribution is difficult to measure, the light emission distribution of the light emitted from the micro light emitting element 100 was found by ray tracing simulation. As shown in graph 401 of FIG. 4 , in some cases the light output from micro-light emitting element 100 increased by a maximum of about 2.5 times compared to the case without microlens 40 . Here, it can be seen that most of the increased light is in the area where the light emission angle is 30 degrees or more.

However, this is useless since the light of the large light exit angle cannot be transmitted from the front to the observer looking at the image display element 200 . In addition, even in the case of condensing light emitted from the micro-light-emitting element 100 through a lens or the like, and projecting an image formed by the image display element 200 on a screen or the like, such as a glasses-type terminal or a HUD (Head Mounted Display), the The light-gathering range of the lens is not large (for example, below 40 degrees), so the light with a large emission angle is still useless.

Graph 402 and graph 403 in FIG. 4 are graphs showing from where the light at an emission angle of 60 degrees or more is emitted from the microlens 40 in the presence of the microlens 40 , where the increase in the light emission amount is significant. Graph 402 of FIG. 4 is a distribution about the height position (Z) from the bottom surface of the microlens 40 , and a graph 403 of FIG. 4 is a distribution about the distance (Ra) from the center of the microlens 40 .

It can be seen from the graph 402 and graph 403 of FIG. 4 that Z of light with a large light emission angle is close to 0 μm, that is, it is mainly emitted from the vicinity of the outer periphery of the microlens 40 .

The results show that by disposing the microlens 40, the light emitted from the light emitting surface 101 of the micro-light emitting element 100 to the direction of the adjacent micro-light-emitting element 100 increases. Such light is reflected by the microlens 40 of the adjacent micro light emitting element 100 to appear as if emitted from the adjacent pixel. That is, by providing the microlens 40 , there is a possibility that light leakage between adjacent micro-light-emitting elements 100 may deteriorate. Here, by providing the partition wall 34 on the outer periphery of the microlens 40, the light emitted in the direction of such adjacent micro light emitting elements 100 can be cut off. Therefore, the problem of light leakage does not occur. In addition, as shown in FIG. 3 , light emitted at a large emission angle α is reflected in the front direction of the micro-light emitting element 100, thereby being effectively utilized. In addition, the emission angle α is an angle corresponding to the centerline direction and the direction in which light is emitted.

At the outer peripheral portion of the microlens 40, light emitted from the height Z at the emission angle α passes through the reflective surface 34S inclined at the angle θw, and is reflected to the center line at an angle of 2×θw+α-π (π radian=180 degrees). That is, the emission angle is converted from α to 2×θw+α-π. For example, in order to reflect light emitted at α=75 degrees toward the center line, θw=52.5 degrees. At this time, the light with α of 60° to 90° passes through the reflective surface 34S to become light emitted at a new emission angle of 0° to 15°. In order to reflect light emitted at α=60 degrees toward the center line, θw=60 degrees. At this time, the light with α of 60° to 90° passes through the reflective surface 34S to become light emitted at a new emission angle of 0° to 30°. In addition, θw is not limited thereto, for example, it is greater than 45 degrees, and generally preferably not less than 45 degrees and not more than 60 degrees.

As shown in FIG. 3 , if the distance from the end of the microlens 40 to the end of the bottom of the reflective surface 34S is set as D, the height Zh at which the light emitted at the emission angle α from the height Z is located on the reflective surface 34S is given by It is represented by the following formula (1).

Zh＝{Z+(D+1/2×Z ² /R)}/{1-1/(tanθw×tanα)} (1)

R is the radius of curvature of the hemispherical surface of the microlens 40 . The larger D is, the larger Zh is, so it is necessary to increase the height of the partition wall 34 . Therefore, in order to facilitate the manufacture of the image display element 200, the smaller D is, the better. That is, it is desirable that the distance from the end of the microlens 40 to the end of the bottom of the reflection surface 34S be as small as possible. If this condition is satisfied and Z/R is also smaller than 1.0, Zh can be approximated by simplifying formula (1) in the manner of Zh≒Z/{1-1/(tanθw×tanα)}.

In the example of FIG. 3 , Z=2 μm, θw=45 degrees, and α=60 degrees, then Zh=4.7 μm. This is because the height of the partition wall 34 relative to the centerline direction is generally lower than the height of the microlens 40 relative to the centerline direction. That is, it can be said that it is sufficient that the height of the partition wall 34 with respect to the centerline direction is equal to or less than the height of the microlens 40 with respect to the centerline direction.

Here, the emission angle distribution of the light emission amount when θw=60 degrees, D=0, and the height of the partition wall 34 is equal to R (=5.8 μm) was simulated. As shown in the graph 404 of FIG. 4 , it can be seen that when the reflection surface 34S of the partition wall 34 is present, the distribution is shifted in the direction of a smaller light emission angle than when there is no reflection surface 34S.

Further, a simulation of light extraction efficiency was performed while varying the magnitude of θw and the height of the partition wall 34 . In the graph 405 of FIG. 4 , the dependence of the light extraction efficiency on θw when the height of the partition wall 34 is equal to R is shown. The emission efficiency (total emission amount) of fully emitted light regardless of the emission angle and the emission efficiency of light with an emission angle of 40 degrees or less (emission angle ≤ 40 degrees) are shown. The light extraction efficiency of light at an emission angle of 40 degrees or less is an indicator of the degree of concentration of observed light in the front direction. As shown in the graph 405 of FIG. 4 , if θw is in the range of 45° to 70°, more than half of the total emitted light can be concentrated in the range below the radiation angle of 40°.

Furthermore, the graph 406 of FIG. 4 shows the dependence of the light extraction efficiency on the height of the partition wall 34 (θw=60 degrees). The higher the partition wall 34 is, the higher the extraction efficiency of light is at an emission angle of 40 degrees or less. However, the partition wall 34 cannot be arbitrarily raised. As shown in FIG. 3 , since the width of the bottom of the partition wall 34 increases when the partition wall 34 is raised, the size of the light exit surface is restricted. Therefore, the height of the partition wall 34 is preferably about the height of the microlens 40 .

As mentioned above, by arranging the microlens 40 to cover the light emitting surface 101 of the micro-light-emitting element 100, the light output can be greatly improved. The partition wall 34 can suppress the light leakage of the adjacent micro-light-emitting elements 100 and at the same time increase the light emitted in the direction of the center line, thereby improving the utilization efficiency of light.

[Second Embodiment]

Another embodiment of the present invention will be described below with reference to FIG. 5 . In addition, for convenience of description, members having the same functions as those described in the above-mentioned embodiment are given the same reference numerals, and the description thereof will not be repeated. The same applies to the third and subsequent embodiments.

In the image display element 200a according to the present embodiment, the structure of the partition wall 34a is different from that of the image display element 200 of the first embodiment. In this embodiment mode, it is intended to realize an image display element having pixels larger than those of the first embodiment mode. In the first embodiment, the micro light emitting element 100 is covered with the embedding material 60, and the partition wall 34 is provided thereon. However, in this embodiment, the partition wall 34 a is directly provided on the drive circuit board 50 without using the embedding material 60 . This form can be adopted when the pixel pitch is large and the space between the micro light emitting elements 100 is large.

In addition, the partition walls 34a are formed to have a height approximately equal to the height of the microlenses 40a. In addition, the height of the partition wall 34a is not limited to this, If it is higher than the bottom surface of the microlens 40a, it may be smaller than the height of the microlens 40a. Therefore, since the height of the partition wall 34 a becomes higher than that of the partition wall 34 in the first embodiment, the partition wall 34 a formed in advance by mold molding can be bonded to the drive circuit board 50 . In the present embodiment, the same light-shielding effect as that of the embedding material 60 is obtained by the partition wall 34 a. Therefore, also in this embodiment, the same effect as that of the first embodiment can be achieved.

[Third Embodiment]

Another embodiment of the present invention will be described below with reference to FIG. 6 . In the image display element 200b of the present embodiment, the shape of the partition wall 34b is different from that of the image display element 200 of the first embodiment. In the first embodiment, the planar shape of the microlens 40 is a circle, and the reflective surface 34S is also formed in a circle so as to be separated from the surface of the microlens 40 by a certain distance. However, as shown in FIG. 6 , the partition wall 34 b may be a shape in which the surface of the reflective surface 34Sb is parallel to the sides of the rectangular pixels 5 . In other words, the cross-sectional shape of the partition wall 34b viewed from the light emitting surface 101 side of the micro-light emitting element 100 may also be rectangular. Also in this embodiment, the same effect as that of the first embodiment can be achieved. In addition, this structure has the advantage of being easy to form the partition wall 34 .

[Fourth embodiment]

Another embodiment of the present invention will be described below with reference to FIG. 7 . In the image display element 200c of the present embodiment, the structure of the partition wall 34c is different from that of the image display element 200 of the first embodiment.

As shown in FIG. 7 , partition wall 34 c of the present embodiment has a structure including partition wall base material 35 and partition wall reflective material 36 . In the partition wall 34c, the surface of the partition wall reflective material 36 formed on the side of the partition wall 34c facing the microlens 40 is the reflective surface 34Sc. When the thickness of the partition wall reflector 36 is substantially constant over the entire side surface, the inclination angle θw of the reflection surface 34Sc is substantially equal to the inclination angle of the side surface of the partition base material 35 . The partition wall base material 35 can be made of, for example, inorganic materials such as SiO ₂ and SiN, and resin materials such as photoresist materials. The partition wall reflective material 36 can be made of, for example, a highly reflective metal film or the like. In addition, as long as the reflection surface 34Sc is a surface that can reflect light well, the partition wall 34c may be constituted by a plurality of members.

As shown in the first embodiment, when trying to form the partition wall 34 with a single reflective material, in the manufacturing process, it is necessary to deposit a metal film higher than the height of the partition wall 34, and then process it by photolithography and dry etching techniques. Into the shape of the partition wall 34 having an inclined surface. Since the height of the partition wall 34 is sometimes several μm, it is necessary to deposit a very thick metal film, but such a thick metal film has large surface irregularities, and it is difficult to deposit the base layer (in this embodiment, the embedding material 60) of the metal film. ) for precise alignment. In addition, since it is desired that the bottom of the reflective surface 34S does not cover the light emitting surface 101 of the micro-light-emitting element 100, as the pixel size of the pixel 5 included in the image display element 200c becomes smaller, it is necessary to precisely align the partition wall 34 to emit light. The necessity of face 101. Therefore, the object of this embodiment is to form the central part (partition wall base material 35 ) of the partition wall 34 c with a transparent material that is easy to perform precise alignment and has few surface irregularities, and cover the surface with the partition wall reflective material 36 to avoid above question.

Openings 37 are formed in the partition reflective material 36 . The opening 37 is preferably formed in a shape covering the entire light exit surface 101 . That is, it is preferable that the partition wall reflector 36 does not overlap the light exit surface 101 . In addition, the bottom of the microlens 40 preferably covers the entire surface of the opening 37 . Also in this embodiment, the same effect as that of the first embodiment can be achieved.

[Fifth Embodiment]

Another embodiment of the present invention will be described below using FIG. 8 . In the image display element 200d of this embodiment, the micro light emitting element 100d is different from the micro light emitting element 100 of the first embodiment. That is, in the compound semiconductor layer 14, the lower surface side of the micro-light-emitting element 100 bonded to the drive circuit substrate 50 has the P electrode 23P and the N-electrode 23N, but the micro-light-emitting element 100d has an electrode provided on the lower surface side of the compound semiconductor layer 14. The common N electrode 30 (upper electrode, second electrode) on the light emitting surface 101 side of the compound semiconductor layer 14 is provided on the P electrode 23Pd (lower electrode, first electrode). In this structure, since there is no need to provide an N-type electrode on the lower surface side of the compound semiconductor layer 14, there is an advantage that it is easy to miniaturize the micro-light-emitting element 100d. The P electrode 23Pd (first electrode) is provided for each micro light emitting element 100d, and the common N electrode 30 (second electrode) is provided for connecting (crossing) the micro light emitting element 100d. In addition, in the case where the P-side layer 13 is arranged on the light emitting direction side, the first electrode serves as an N electrode, and the second electrode serves as a P electrode.

In the image display element 200d, outside the pixel region 1, the common N electrode 30 is connected to the N driving electrode 52 on the driving circuit substrate 50d. Here, the connection method is not directly related to the essence of the present invention and is not shown in the figure. The P electrode 23Pd is connected to the P drive electrode 51d on the drive circuit board 50d. The current supplied from the drive circuit substrate 50d to the micro light emitting element 100d is transmitted from the P drive electrode 51d to the P side layer 13 via the P electrode 23Pd. The current passing through the light-emitting layer 12 from the P-side layer 13 flows from the N-side layer 11 to the N drive electrode 52 via the common N electrode 30 . In this way, the micro light emitting element 100d emits light with a predetermined intensity according to the amount of current supplied from the driving circuit substrate 50d.

Like the micro light emitting element 100 of the first embodiment, each micro light emitting element 100d is electrically isolated by the embedding material 60 . In particular, in the micro-light-emitting element 100d, the side surfaces around the light-emitting layer 12 are formed as inclined surfaces, and the inclined surfaces are opened in the light emission direction of about 30 degrees to 60 degrees. In this way, the light extraction efficiency from the micro-light-emitting element 100d can be improved by opening and inclining the surrounding side surfaces of the light-emitting layer 12 in the light-emitting direction. The inclined portion formed on the surface opposite to the light exit surface 101d of the micro light emitting element 100d is covered with a protective film 17 which is a transparent insulating film. The opposite side of the protective film 17 to the compound semiconductor layer 14 is preferably covered with a highly reflective metal film.

Usually, the common N electrode 30 is often made of a transparent conductive film, but in this embodiment, the partition wall reflective material 36 described in the fourth embodiment is used as the common N electrode 30 . The reflective surface 34Sc of the partition wall 34c needs to be a surface that reflects light well, and a metal film such as silver or aluminum is used as part of it in many cases. In this way, the manufacturing process can be simplified by using the constituent material of the partition wall 34 c as the common N electrode 30 . The partition reflector 36 is adjacent to the N-side layer 11 on the light exit surface 101d. That is, the opening 37 formed in the partition wall reflector 36 is not the entire light exit surface 101d, but is provided inside the light exit surface 101d. The structure of the microlens 40 is the same as that of the fourth embodiment. Also in this embodiment, the same effect as that of the first embodiment can be achieved.

[Sixth embodiment]

Another embodiment of the present invention will be described below with reference to FIGS. 9 and 10 . A schematic cross-sectional view of part A-A of FIG. 10 is shown in FIG. 9 . The image display element 200 e of the present embodiment is a full-color display element of the three primary colors of RGB, and the pixel 5 includes a blue sub-pixel 6 , a red sub-pixel 7 , and a green sub-pixel 8 . As shown in FIG. 10 , the blue sub-pixel 6 includes a blue micro-light emitting element (micro-light-emitting element) 100B, and the red sub-pixel 7 includes a red micro-light-emitting element (micro-light-emitting element) 100R. Furthermore, as shown in FIG. 10 , the pixel 5 includes two green sub-pixels 8 including one green micro-light-emitting element (micro-light-emitting element) 100G.

The red micro light emitting element 100R is composed of a blue micro LED (micro LED) 105 emitting blue light and a red wavelength converting portion (wavelength converting portion) 32 . Similarly, green micro light emitting element 100G is composed of blue micro LED 105 and green wavelength conversion unit (wavelength conversion unit) 33 . Blue micro light emitting element 100B is composed of blue micro LED 105 and transparent part 31 .

The blue micro LED 105 is the same as the micro light emitting element 100 of the first embodiment. The light emitting surface 101B of the blue micro-light emitting element 100B is the upper surface of the transparent portion 31 . In addition, the light emitting surface 101R of the red micro-light emitting element 100R is the upper surface of the red wavelength conversion part 32 , and the light emitting surface 101G of the green micro light emitting element 100G is the upper surface of the green wavelength converting part 33 . In addition, in this configuration, blue light is used as excitation light for red and green, and a wavelength converter for down-converting the wavelength is provided, and the excitation light is directly used for blue light. In addition, down-conversion herein means extending the wavelength of excitation light (reducing the energy of light).

However, it is also possible to use near-ultraviolet and ultraviolet rays as excitation light, and down-convert the excitation light to generate blue light. In addition, in the following description, when there is no need to distinguish the transparent part 31, the red wavelength converting part 32, and the green wavelength converting part 33, only the wavelength converting part will be described.

The blue micro-light emitting element 100B, the red micro-light-emitting element 100R, and the green micro-light-emitting element 100G are the same as the first embodiment, and the surrounding areas other than the light emission direction side are covered with the embedding material 60e. That is, not only the blue micro LED 105 but also the transparent portion 31 , the red wavelength conversion portion 32 , and the green wavelength conversion portion 33 are covered with the embedding material 60 e around the periphery other than the light emission direction side.

The microlens 40 and the partition wall 34c are the same as those of the fourth embodiment shown in FIG. 7 . The difference from FIG. 7 is that the light exit surfaces 101B, 101R and 101G are respectively located on the upper surfaces of the transparent part 31 , the red wavelength conversion part 32 and the green wavelength conversion part 33 . Also in this embodiment, the same effect as that of the first embodiment can be achieved. In addition, in the present embodiment, there is an advantage that full-color display with high luminance can be realized with a single image display element 200e by using a nitride semiconductor with high luminous efficiency and good durability.

[Seventh Embodiment]

Another embodiment of the present invention will be described below with reference to FIGS. 11 and 12 . The image display element 200f of the present embodiment is a full-color display element similar to the image display element 200e of the sixth embodiment. The difference from the image display element 200e lies in the shape and configuration of the blue micro LED 105f that generates excitation light, and the transparent part 31, the red wavelength conversion part (wavelength conversion part) 32, and the green wavelength conversion part (wavelength conversion part) 33 of different shapes.

In order to improve the light extraction efficiency of the blue micro LED 105f that generates the excitation light, the side surface 16S around the light emitting layer 12 is opened in the light emitting direction, inclined at an angle of not less than 30 degrees and not more than 60 degrees with respect to the light emitting layer 12, and The side surface 11S of the N-side layer 11 is also inclined at an angle θb of 70 degrees or more and 85 degrees or less with respect to the common N electrode 30 . These inclined surfaces have high light transmittance. For example, by covering the compound semiconductor with a transparent insulating film and covering the outer side of the insulating film with a highly reflective metal film such as aluminum or silver, the light extraction efficiency can be further improved.

As shown in FIG. 11, in the image display element 200f, the light-emitting layer 12 and the P-side layer 13 are disposed on the drive circuit substrate 50d side, the P electrode 23P (first electrode) is disposed on the drive circuit substrate 50d side, and the common N electrode 30 ( second electrode) is disposed on the light exit surface side. However, even if the shape of the blue micro LED 105f from the image display element 200f is not changed, and the p-side layer 13 and the light emitting layer 12 are arranged on the light exit surface side, the same effect as that of the image display element 200f can be obtained. In this case, the first electrode is an N electrode, and the second electrode is a common P electrode. In addition, the polarity of the drive electrodes of the drive circuit board 50d is also reversed.

The side walls of transparent portion 31 , red wavelength converting portion 32 , and green wavelength converting portion 33 are also open in the light emitting direction, preferably inclined at an angle θs of 45° to 85° with respect to common N electrode 30 .

The light extraction efficiency from the wavelength conversion part can be improved by inclining the side wall of the wavelength conversion part to open with respect to the light emission direction. In addition, the light extraction efficiency from the transparent portion 31 can be improved by making the side wall of the transparent portion 31 open and inclined with respect to the light emission direction.

Furthermore, the side walls of the transparent portion 31 , the red wavelength conversion portion 32 , and the green wavelength conversion portion 33 are also covered with a highly reflective metal film, whereby the light extraction efficiency can be further improved.

In addition, in this embodiment, a structure using a transparent conductive film is adopted as the common N electrode 30 . In such a structure, the embedding material 60 is formed after the blue micro LED 105f of the excitation light source is attached to the driving circuit substrate 50d, and the common N electrode 30 is formed thereon. After that, the transparent part 31 , the red wavelength conversion part 32 , the green wavelength conversion part 33 , and the embedding material 61 covering these wavelength conversion parts are formed.

In this embodiment, FIG. 12 shows the simulation results of the light emission angle distributions of blue light and red light. Graph 1201 of FIG. 12 shows a comparison with and without microlens 40 for blue light. Graph 1202 of FIG. 12 shows a comparison of cases with and without microlenses 40 for red light. In any of blue light and red light, as shown in Table 1 and Table 2 below, in the case of microlens 40, compared with the case without microlens 40, the amount of light emission (in Table 1 and Table 2 external emissions) increased substantially. Especially for red light, the amount of light emission was greatly increased by about 2 times.

[Table 1]

with microlens no microlens Compound semiconductor layer loss 25.2% 37.2% Transparency loss 5.8% 15.6% In-lens loss 6.4% 0% external shot 62.3% 46.4% total 99.8% 99.2%

[Table 2]

with microlens no microlens Compound semiconductor layer loss 14.6% 31.4% Red wavelength conversion part loss 14.6% 35.2% In-lens loss 4.2% 0% external shot 66.4% 32.8% total 99.8% 99.4%

However, the effect of the microlens 40 in the case of the blue light that directly emits the excitation light to the outside of the blue sub-pixel 6 and the red light that generates red light in the red wavelength converting portion 32f is large in the light emission angle distribution. s difference. In the case of blue light, the light emitted by the microlens 40 in the range of the light emission angle of 20 degrees or more and 60 degrees or less increases, but in the case of red light, the light emission amount decreases around the light emission angle of 70 degrees. A substantial increase. The distribution diagram 1203 of FIG. 12 shows the emission position distribution of the red light emitted during the period in which the light emission angle is not less than 65 degrees and not more than 75 degrees. In this case, it can be seen that most of the red light is emitted from the outer peripheral portion of the microlens 40 .

From this result, it can be easily inferred that the effect of the reflective surface 34Sc of the partition wall 34c is greater for red light than for blue light. That is, for a full-color display element like the image display element 200f, the shape of the partition wall 34c should be designed to maximize the effect on red light. In the example of the graph 1202 in FIG. 12 , since it is preferable that the light emitted at an angle of 70 degrees is parallel to the center line of the microlens 40 , the inclination angle θw of the reflection surface 34Sc is preferably 55 degrees.

In the case of the reflective surface 34Sc provided with the above conditions, the light emission angle distribution was simulated. The case of blue light is shown in diagram 1204 of FIG. 12 and the case of red light is shown in diagram 1205 of FIG. 12 . The height of the partition wall 34c is set to be equal to the radius of the microlens 40, D=0. Table 3 shows the amount of externally emitted light at an emission angle of 40 degrees or less in blue light and red light. As shown in Table 3, since the reflective surface 34Sc is provided, the externally emitted light increases in the region where the light emission angle is small. The effect increases by 18% in blue light and 120% in red light. In this way, the reflective surface 34Sc can greatly increase the amount of light emitted from the micro-light-emitting element toward the centerline of the micro-lens 40 . For green light, the same effect as that of red light can be expected.

[table 3]

no reflective surface with reflective surface blu ray 25.4% 30.0% red light 16.2% 35.6%

In order to improve the luminance in the front direction of the micro light emitting element 100f, the contact angle θc of the microlens 40 is important. As shown in FIG. 3 , the contact angle θc is an angle formed by the bottom of the microlens 40 and the surface of the microlens 40 . Specifically, when the surface of the microlens 40 is spherical, θc=90 degrees when the center of the microlens 40 overlaps the light exit surface, and θc becomes smaller as the center moves downward from the light exit surface.

Graph 1206 of FIG. 12 shows simulation results of the θc dependence of the light extraction efficiency at a light emission angle of 40 degrees or less and the light extraction efficiency in the absence of the reflective surface 34Sc. As θc becomes smaller, the light extraction efficiency from the microlens 40 to the outside decreases. On the other hand, although the light extraction efficiency decreases at a light emission angle of 40 degrees or less, it maintains a substantially constant value when θc≧74 degrees. Thus, in order to increase the luminance in the front direction of the micro-light-emitting element, it is preferable to keep the contact angle θc at 74 degrees or more.

Also in this embodiment, the same effect as that of the first embodiment can be achieved.

[Eighth Embodiment]

Another embodiment of the present invention will be described below using FIG. 13 . The image display element 200g of the present embodiment is a full-color display element similar to the image display element 200f of the seventh embodiment. The difference is that the wavelength conversion part is arranged in the partition wall 34g, and the microlens 40 is provided thereon.

As described in the seventh embodiment, the light extraction efficiency from the wavelength conversion part can be improved by inclining the side wall of the wavelength conversion part to open with respect to the light emission direction. On the other hand, in order to reflect light emitted from the outer peripheral portion of the microlens 40 at a large light emission angle in the direction of the center line of the microlens 40, it is necessary to make the reflection surface 34Sg of the partition wall 34g also open and inclined with respect to the light emission direction. . Therefore, by arranging the wavelength conversion part in addition to the microlens 40 inside the partition wall 34g, the light extraction efficiency can be improved, and the light output of the micro-light-emitting element to the front direction can be enhanced, thereby improving the luminous efficiency. In this specification, the blue micro-light emitting element 100Bg, the red micro-light-emitting element 100Rg and the green micro-light-emitting element 100Gg may be collectively referred to as a micro-light-emitting element.

In addition, as shown in FIG. 13 , the height of the partition wall 34 g in the centerline direction may be smaller than the height of the microlens 40 in the centerline direction. As shown in the graph 406 of FIG. 4 , it can be considered that the light extraction efficiency of light emitted in the direction of the center line of the microlens 40 increases as the height of the partition wall 34 g increases. However, if the number of partition walls 34g increases, the light exit surface becomes smaller. Due to the reduction of the light exit surface, the light emission efficiency may decrease. In addition, the lower the partition wall 34g is, the easier it is to manufacture the image display element. Therefore, the positive effect of increasing the height of the partition wall 34g can be compared with the negative effect of reducing the light exit surface, and an optimal value of the height of the partition wall 34g can be selected.

In this embodiment, the structure of the blue micro LED 105f as an excitation light source on the drive circuit board 50d is the same as that of the seventh embodiment. The structure in which the partition wall base material 34Bg is arranged on the common N electrode 30 and the partition wall reflective material (to form the reflective surface 34Sg) is arranged thereon is the same as that of the fourth embodiment shown in FIG. 7 . In FIG. 7 , the opening 37 of the partition wall reflector 36 completely covers the light emitting surface 101 of the micro light emitting element 100 , but in this embodiment, the opening 37 g covers a part of the upper surface of the blue micro LED 105 f. This is for suppressing light leakage from the wavelength converting portion to the drive circuit board 50d side when the embedding material 60g does not have light-shielding properties. Also in this embodiment, the same effect as that of the first embodiment can be achieved.

[Ninth Embodiment]

Another embodiment of the present invention will be described below with reference to FIGS. 14 and 15 . The image display element 200h of the present embodiment is the same full-color display element as the image display element 200f of the seventh embodiment, but the difference is that, as the micro-light-emitting element, QLED (Quantum dot light-emitting diode: quantum dot LED) is used. ). In this embodiment, the red micro-light emitting element 100Rh is composed of a P driving electrode 51d (first electrode), a red light emitting layer 110R formed thereon, and a common N electrode 30 (second electrode) formed thereon.

As shown in FIG. 15 , the red light emitting layer 110R is provided with an electron transport layer 121 and a hole transport layer 122 on both sides of the quantum dot layer 120 . The red light emitting layer 110R emits light by injecting electrons and holes from the electron transport layer 121 and the hole transport layer 122 , respectively, and recombining in quantum dots included in the quantum dot layer 120 . By changing the core size of quantum dots, the emission wavelength can be controlled. Therefore, the blue micro-light emitting element 100Bh and the green micro-light emitting element 100Gh may also be composed of QLEDs. In addition, in the following, when it is not necessary to distinguish colors, it may be described only as the light emitting layer 110 . Since the configuration details of the QLED are not directly related to the essence of the present invention, they are not covered in this description.

The common N electrode 30 is a transparent conductive film. It is preferable that the surface of the P drive electrode 51d has a high reflectance of visible light. The light emitting surface in this embodiment is the surface of each light emitting layer 110B, 110R, 110G. In addition, by arranging the electron transport layer 121 on the side of the driving circuit substrate 50d and the hole transport layer 122 on the side of the light emitting surface, QLEDs can also be arranged with opposite polarities. In this case, the first electrode is an N electrode, and the second electrode is a common P electrode.

In the example shown in FIG. 4 , microlenses 40 made of transparent resin are disposed on compound semiconductor layer 14 having a refractive index of about 2.4. In addition, in the graph 1202 of FIG. 12 , the microlens 40 made of transparent resin is arranged on the wavelength converting portion having a refractive index of about 1.6. In either case, the microlens 40 achieves a very large improvement in light extraction efficiency. In this way, improvement in light extraction efficiency can be achieved by the microlens 40 even when the refractive index of the light exit surface varies greatly. Although the refractive index of the light exit surface of the QLED cannot be accurately measured, it can be inferred from the refractive index of the resin layer that constitutes the quantum dot material, the electron transport layer 121 and the hole transport layer 122, it can be considered that it is similar to the example in Figure 4 and Figure 12 Not much difference. Therefore, the same effect as the microlens 40 can be expected also in this embodiment using QLEDs.

The partition wall 34 c is made of metal, and as shown in FIG. 14 , since it is in direct contact with the common N electrode 30 in the pixel, it can also be used as a part of the N electrode wiring. In particular, in order to reduce light absorption by the common N electrode 30 , it is necessary to make the common N electrode 30 thinner, and thus the resistance of the common N electrode 30 increases. By using the partition wall 34 c as a part of the wiring common to the N electrode 30 , an increase in resistance on the N electrode side can be suppressed. In the present embodiment, the microlens 40 is arranged to cover the light emitting surface, and further by arranging the partition wall 34c, light leakage to adjacent micro light emitting elements can be suppressed.

[modified example]

As a modified example of the ninth embodiment, each light emitting layer 110B, 110R, 110G may use an organic LED (OLED: organic light-emitting diode) instead of a QLED. Like the QLED, the OLED has a structure in which a light emitting layer is disposed between an electron transport layer 121 and a hole transport layer 122 .

[Tenth Embodiment]

Another embodiment of the present invention will be described below with reference to FIG. 16 . The image display element 200i of this embodiment is the same as that of the ninth embodiment in that QLED is used as the micro light emitting element, but it is different from the ninth embodiment in that the micro light emitting element includes a P electrode 23Pi (first electrode) having a concave portion. different. In other words, the P electrode 23Pi is formed in a concave shape on the side opposite to the light exit surface side of the micro light emitting element. The light-emitting layers 110B, 110R, and 110G are disposed inside the concave portion formed on the P electrode 23Pi. In addition, by arranging the electron transport layer 121 on the side of the driving circuit substrate 50d and the hole transport layer 122 on the side of the light emitting surface, QLEDs can also be arranged with opposite polarities. In this case, the first electrode is an N electrode, the second electrode is a common P electrode, and the N electrode has a structure having a concave shape.

As shown in FIG. 16 , the side wall 23S of the concave portion formed on the P electrode 23Pi is inclined so that the inclination angle θq with respect to the drive circuit substrate 50d is smaller than 90 degrees. θq is preferably not less than 30 degrees and not more than 60 degrees. The surface of the P electrode 23Pi is formed of a highly reflective metal material.

Since QLED emits light isotropically, in FIG. 16, it also emits light in the horizontal direction. By upwardly reflecting light traveling in this horizontal direction, light leakage to adjacent micro-light emitting elements can be suppressed, and light extraction efficiency can be improved. The light emitting layer 110 may be in contact with the sidewall 23S, but the light emitting layer 110 is preferably disposed at the bottom of the concave portion formed on the P electrode 23Pi without directly contacting the sidewall 23S. The transparent insulating film 18 is preferably disposed between the side wall of the light emitting layer 110 and the side wall 23S. In this case, the light emitted in the horizontal direction from the light emitting layer 110 passes through the transparent insulating film 18 and is reflected by the side wall 23S to be emitted upward. Therefore, the light emitting surface 101i becomes the opening of the concave portion of the P electrode 23Pi.

The microlens 40 is formed so as to cover the light exit surface 101i. The partition wall 34 c is arranged around the microlens 40 . This point is the same as that of the first embodiment.

In addition, in the image display element 200i, the periphery in the direction parallel to the light emitting surface of the P electrode 23Pi is covered with the first insulating film 19, and the periphery in the direction parallel to the light emitting surface of the common N electrode 30 is covered with the second insulating film 20. coverage, which is different from other implementations.

The manufacturing process of the image display element 200i of this embodiment is demonstrated below. The first insulating film 19 is formed on the driving circuit substrate 50d, and an opening is provided on the P driving electrode 51d. The inclination angle of the side wall of the opening is controlled to be θq. A highly reflective metal thin film forming a P electrode is deposited thereon, and processed into a P electrode 23Pi forming a concave portion.

The first insulating film 19 may be an inorganic insulating film such as SiO ₂ or SiN, or may be a resin such as polyimide or silicone. The highly reflective metals used as the material of the P electrode 23Pi are silver and aluminum. Next, the light emitting layer 110 is sequentially formed. The material of the light emitting layer 110 may be directly applied for patterning, or the light emitting layer 110 formed on another substrate may be transferred onto the P electrode 23Pi. Next, a transparent insulating film 18 is formed. Furthermore, by forming the second insulating film 20 , openings are provided in the light emitting layer 110 , and the common N electrode 30 is further formed. Both the transparent insulating film 18 and the second insulating film 20 are transparent insulating films and may be formed simultaneously. The common N electrode 30 is a transparent conductive film. The method of forming the microlens 40 and the partition wall 34c is the same as that of the first embodiment. In this embodiment as well, the microlens 40 is arranged so as to cover the light exit surface 101i, and by further arranging the partition wall 34c, the same effect as that of the first embodiment can be achieved.

[Eleventh Embodiment]

Another embodiment of the present invention will be described below with reference to FIG. 17 . The image display element 200j of this embodiment is similar to the seventh embodiment shown in FIG. 11 , but differs in that the functions of the wavelength converting portion and the microlens are integrated.

The red micro-light-emitting element (micro-light-emitting element) 100Rj in this embodiment is composed of blue micro-LEDs (micro-LEDs) 105f and a red wavelength conversion part (wavelength conversion part) 41 arranged on the upper surface thereof.

The red wavelength conversion part 41 is the same as the microlens 40 in other embodiments, and has a shape (for example, a hemispherical shape) including a convex curved surface in the light emitting direction, but contains a wavelength conversion material that down-converts blue light into red light. In one point, it is different from the microlens 40 .

In the red wavelength conversion part 41 , for example, a wavelength conversion substance such as quantum dots or quantum rods emitting red light, phosphors, or dyes is dispersed on a transparent resin. Similarly, in the green micro light-emitting element 100Gj, the hemispherical green wavelength conversion part 42 is arranged on the blue micro LED 105f. The blue micro-light-emitting element 100Bj has the transparent micro-lens 40 similarly to other embodiments. This is because wavelength conversion of the light emitted from the blue micro LED 105f is not required.

A partition wall 34 c is arranged around the microlens 40 , the red wavelength conversion unit 41 , and the green wavelength conversion unit 42 . In addition, the bottom surfaces of the microlens 40 , the red wavelength conversion portion 41 , and the green wavelength conversion portion 42 cover the opening portion 37 of the partition wall reflective material (forming the reflective surface 34Sj).

In FIG. 17 , the partition wall reflector covers part of the light exit surface 102 of the blue micro LED 105 f , but the opening 37 may completely cover the light exit surface 102 . In other words, the partition wall reflective material may not cover a portion of the light emitting surface 102 . This is because when the embedding material 60 has light-shielding properties, even if the opening 37 completely covers the light exit surface 102 , there is little light leakage to the adjacent micro-light-emitting elements.

The concentration distribution of the wavelength converting substance in the red wavelength converting portion 41 does not necessarily need to be uniform. For example, a layer with a high concentration of the wavelength conversion substance may be disposed at the bottom of the red wavelength conversion portion 41 and a layer with a low concentration of the wavelength conversion substance may be disposed at the top. Alternatively, a layer having a high concentration of the wavelength conversion substance may be arranged in the central part of the red wavelength conversion part 41, and the concentration of the wavelength conversion substance becomes thinner toward the outer side from the central part. In addition, the configuration of the concentration of the wavelength converting substance may be reversed from the above configuration. The same is true for the green wavelength conversion section 42 .

In the blue micro light emitting element 100Bj, the effects of the microlens 40 and the partition wall 34c are the same as those of the first embodiment. In addition, the surface of the outer peripheral portion of the hemispherical red wavelength conversion portion 41 has an approximately vertical inclination.

In the red wavelength conversion portion 41 , light emitted at a light emission angle approximately in the horizontal direction is easily emitted from the outer peripheral portion of the red wavelength conversion portion 41 having an approximately vertical inclination. Since the diameter of the outer peripheral portion of the red wavelength converting portion 41 is the largest, a large amount of light is emitted at an angle approximately in the horizontal direction, and thus a large amount of light is emitted from the outer peripheral portion at a large light emission angle, as in the seventh embodiment. Therefore, according to this embodiment, the same effect as that of the seventh embodiment is produced. The same is true for the green micro-light emitting element 100Gj.

As described above, the partition wall 34c arranged around the red wavelength conversion part 41 (green wavelength conversion part 42) in the direction parallel to the light exit surface 102 changes the shape of the red wavelength conversion part 41 (green wavelength conversion part 42). As a shape including a convex curved surface in the light emission direction, the side surface of the partition wall 34c facing the red wavelength conversion part 41 (green wavelength conversion part 42) is inclined to be opened with respect to the light emission direction, and serves as a reflection surface for reflecting light . This suppresses light leakage to adjacent micro-light-emitting elements and reflects light with a large light emission angle in the direction of the center line of the microlens 40 to increase the intensity of light emitted in the direction of the center line.

[Twelfth Embodiment]

Another embodiment of the present invention will be described below using FIG. 18 . The image display element 200k of this embodiment is similar to the image display element 200e of the sixth embodiment shown in FIG. The point of disposing the dielectric multilayer film 45 is different.

By disposing the microlens 40 on the light-emitting surface 101R of the micro-light-emitting element 100R and the light-emitting surface 101G of the micro-light-emitting element 100G, the emission amount of the down-converted red light and green light increases. The emission amount of the blue light of the excitation light also increases.

When the optical density of the red wavelength conversion part 32 and the green wavelength conversion part 33 to blue light is not large enough, blue light as excitation light is emitted from the red sub-pixel 7 and the green sub-pixel 8, and light is emitted from these sub-pixels. The color purity of red light and green light is reduced. On the other hand, by disposing the dielectric multilayer film 45 that reflects the excitation light on the surface of the microlens 40 and transmits the down-converted red light and green light, the emission of the excitation light from the red sub-pixel 7 or the green sub-pixel 8 is reduced. , can improve color purity. Also in this embodiment, by arranging the microlens 40 so as to cover the light exit surface, and further arranging the partition wall 34c, the same effect as that of the first embodiment can be achieved.

[Thirteenth Embodiment]

Another embodiment of the present invention will be described below with reference to FIG. 19 . The image display element 2001 of this embodiment is similar to the image display element 200e of the sixth embodiment shown in FIG. Filter material) is different in that the microlens 40Y that excites the light-absorbing material is different.

As described in the twelfth embodiment, there are cases where it is necessary to prevent the emission of blue light (excitation light) from the red sub-pixel 7 and the green sub-pixel 8 . In this case, for example, by using a microlens containing dyes (filter material, etc.) Emission of blue light from sub-pixel 7 and green sub-pixel 8 . In this way, even if the blue light-absorbing substance is contained in the microlens 40Y containing the excitation light-absorbing substance, red light and green light will not be greatly affected, so the microlens 40Y containing the excitation light-absorbing substance and the partition wall will not be damaged. 34c effect. In this embodiment, by arranging the microlens 40Y containing the excited light-absorbing substance so as to cover the light exit surface, and further arranging the partition wall 34c, the same effect as that of the first embodiment can be achieved.

[Summarize]

The image display element (200) according to the first aspect of the present invention is an image display element comprising a plurality of micro-light-emitting elements (100) arranged in an array, comprising: supplying current to the micro-light-emitting elements and making the micro-light-emitting elements emit light The driving circuit substrate (50) of the driving circuit, the micro-light-emitting element, the micro-lens (40) in contact with the light-emitting surface (101) of the micro-light-emitting element; and in a direction parallel to the light-emitting surface A partition wall (34) arranged around the microlens, the side of the partition wall facing the microlens is a reflective surface that is inclined and reflects light in a manner opened relative to the light emitting direction.

According to the above configuration, the partition wall is arranged around the microlens in a direction parallel to the light exit surface. Therefore, light leakage to adjacent micro light emitting elements can be suppressed. In addition, according to the structure, the side face of the partition wall facing the microlens is a reflective surface that is inclined in an open manner with respect to a light emission direction and that reflects light. Therefore, the path of light emitted from the microlens is reflected by the reflective surface and changed to be along the front direction of the micro light emitting element. Therefore, by strengthening the light output in the front direction of the micro-light-emitting element, the luminous efficiency can be improved.

The image display element (200) according to the second aspect of the present invention is preferably in the first aspect, the micro-light-emitting element (100) may be a micro-LED comprising compound semiconductor crystals.

According to the image display element (200) of the third aspect of the present invention, preferably in the first aspect, the bottom surface of the microlens (40) covers the light emitting surface (101) of the micro light emitting element (100) overall.

In the image display element (200) according to the fourth aspect of the present invention, preferably in the first aspect, the inclination angle of the reflection surface is 85 degrees or less.

In the image display element (200) according to the fifth aspect of the present invention, preferably in the first aspect, the surface of the microlens (40) is a spherical surface, and the center of the spherical surface is relative to the center of the light exit surface (101). The center is located within ±1 μm.

In the image display element (200a) according to the sixth aspect of the present invention, preferably in any one of the first to fifth aspects, the partition wall (34a) may be formed in contact with the surface of the driving circuit substrate (50). When the pixel pitch is large and the space between the micro light emitting elements is large, the above configuration can be adopted. In addition, according to the above configuration, since the height of the partition wall becomes high, the partition wall formed by mold molding in advance can be bonded to the drive circuit board.

In the image display element (200b) according to the seventh aspect of the present invention, in any one of the first to sixth aspects, the partition wall ( The shape of 34b) can also be rectangular.

According to the image display element (200c) of the eighth aspect of the present invention, in any one of the first to seventh aspects, the partition wall (34c) may also include a partition wall base material (35) made of a transparent material and A partition wall reflective material (36) covering the partition wall base material and composed of a highly reflective metal film.

If a single reflective material is to be used to form the partition wall, a metal film higher than the height of the partition wall must be deposited, and processed into a partition wall with an inclined surface by photolithography and dry etching techniques. Since the height of the partition wall may be several μm, a very thick metal film is required, but the surface of such a thick metal film has large unevenness, making it difficult to precisely align the base layer. In addition, since it is desired that the bottom of the side wall does not cover the light exit surface, it is necessary to precisely align the partition wall with the light exit surface as the pixel size of the image display device becomes smaller. Therefore, the above-mentioned problems can be avoided by forming the base material of the partition wall from a transparent material that can easily be precisely aligned, and covering the surface with a partition wall reflective material.

According to the image display element (200d) of the ninth aspect of the present invention, in any one of the first to eighth aspects, in the micro-light-emitting element (100d), the surface of the micro-light-emitting element is opposite to the light emitting surface There is a first electrode (P electrode 23Pd) on the side surface, and in the micro light emitting element, the light emitting surface side of the micro light emitting element has a second electrode (common N electrode 30). According to the above structure, since it is not necessary to provide both the first electrode and the second electrode on the light exit surface and the opposite surface, it is easy to miniaturize the micro light emitting element.

According to the image display element (200d) of the tenth aspect of the present invention, in the ninth aspect, the partition wall (34c) may also be configured as a wiring connected to the second electrode (common N electrode 30). part. According to the above configuration, by using the partition wall as a part of the wiring common to the N-type electrode, it is possible to suppress an increase in resistance on the N-type electrode side.

According to the image display element (200e) of the eleventh aspect of the present invention, in any one of the first to tenth aspects, the micro light emitting element (100R, 100G, 100B) may have a micro LED ( 105) and a wavelength conversion part (32, 33) extending the wavelength of the excitation light emitted by the micro LED, the light emitting surface of the micro LED may also be the upper surface of the wavelength conversion part.

According to the image display element (200e) of the twelfth aspect of the present invention, in any one of the first to tenth aspects, the micro-light-emitting element (100R, 100G, 100B) may have a micro-LED ( 105) and a transparent part (31) arranged on the micro LED, the light emitting surface of the micro LED may also be the upper surface of the transparent part.

According to the image display element (200f) according to the thirteenth aspect of the present invention, in the eleventh aspect, the surface constituting the side wall of the wavelength conversion portion (32f, 33f) in a direction parallel to the light exit surface It may also be a face that is inclined so as to open in the light emission direction. The light extraction efficiency from the wavelength conversion part can be improved by inclining the side wall of the wavelength conversion part to open with respect to the light emission direction.

According to the image display element (200f) of the fourteenth aspect of the present invention, in the twelfth aspect, the surface constituting the side wall of the transparent portion (31f) in the direction parallel to the light exit surface may be A face that slopes in such a way that it opens in the direction of light emission. The light extraction efficiency from the transparent part can be improved by making the side wall of the transparent part open and inclined with respect to the light emission direction.

According to the image display element (200f) of the fifteenth aspect of the present invention, in the eleventh or thirteenth aspect, the wavelength conversion part (32f, 33f) and the The side wall in the direction parallel to the light exit surface. According to the above configuration, the light extraction efficiency of the micro-light-emitting element can be further improved compared to the case where the sidewall of the wavelength converting portion is not covered with a highly reflective metal film.

According to the image display element (200f) of the sixteenth aspect of the present invention, in the twelfth or fourteenth aspect, the light emitting part and the transparent part (31f) may be covered with a highly reflective metal film. The side walls in the direction parallel to the face. According to the above structure, the light extraction efficiency of the micro-light-emitting element can be further improved compared to the case where the side wall of the transparent portion is not covered with the highly reflective metal film.

According to the image display element (200g) of the seventeenth aspect of the present invention, in the eleventh, thirteenth or fifteenth aspect, the wavelength conversion part (32g, 33g) may also be arranged on the partition wall Inside (34g), the wavelength converting portion and the microlens (40) are laminated in this order.

As described above, the light extraction efficiency from the wavelength conversion part can be improved by inclining the side wall of the wavelength conversion part to open with respect to the light emission direction. On the other hand, in order to reflect light emitted at a large emission angle from the outer periphery of the microlens toward the center line, it is also necessary to incline the reflection surface of the partition wall with respect to the light emission direction. Therefore, by arranging the wavelength conversion portion and the microlens inside the partition wall, the light extraction efficiency can be improved, and the light output in the front direction of the micro light-emitting element can be enhanced to improve the luminous efficiency.

According to the image display element (200g) of the eighteenth aspect of the present invention, in the eleventh aspect, the reflective surface may cover the periphery of the wavelength converting portion in a direction parallel to the light exit surface. .

According to the image display element (200g) of the nineteenth aspect of the present invention, in the first aspect, the height of the reflective surface in the centerline direction may be smaller than the height of the microlens in the centerline direction.

According to the image display element of the twentieth aspect of the present invention, in the first aspect, the micro-light emitting element (100Rh) may also have a quantum dot layer (120) containing quantum dots, and the micro-light emitting element (100Rh ) is a quantum dot LED that emits light by passing electricity to the quantum dot layer.

According to the image display element (200i) of the twenty-first aspect of the present invention, in the first aspect, the micro-light-emitting element may also be an organic LED.

According to the image display element (200i) of the twenty-second aspect of the present invention, in the ninth aspect, the first electrode (P electrode 23Pi) may also be formed in a concave shape on the side opposite to the light emitting surface side. . Since the micro-light-emitting element emits light isotropically, it also emits light in the horizontal direction. By upwardly reflecting light traveling in the horizontal direction, light leakage to adjacent micro-light emitting elements can be suppressed, and light extraction efficiency can be improved.

According to the image display element (200k) of the twenty-third aspect of the present invention, in the eleventh aspect, on the light exit surface emitting the light of the microlens (40), a device reflecting the excitation A dielectric multilayer film (45) that transmits light and transmits light of the extended wavelength. According to the above structure, the emission of excitation light from the micro-light-emitting elements emitting red and green light can be reduced, and the color purity can be improved.

According to the image display element (200l) of the twenty-fourth aspect of the present invention, in the eleventh aspect, the microlens (40Y) may also include a Filter material (blue light absorbing filter material). According to the above structure, emission of excitation light from the micro-light emitting element can be reduced.

The image display element (200j) according to the twenty-fifth aspect of the present invention is an image display element including a plurality of micro-light emitting elements (100Rj, 100Bj, 100Gj) arranged in an array, and sequentially stacked: The driving circuit substrate (50d) of the driving circuit for current and making it emit light, the micro-light-emitting element, the wavelength conversion part (50d) that prolongs the wavelength of the excitation light emitted by the micro-light-emitting element, and has a a partition wall (34c) around the wavelength conversion part in a direction parallel to the light emitting surface of the light emitting element, the wavelength conversion part is formed in a shape including a curved surface protruding along the light emission direction, and the partition wall faces the The side surface of the wavelength converting portion is a reflective surface that is inclined so as to be open with respect to a light emitting direction and reflects light. According to the above configuration, the luminous efficiency can be improved by enhancing the light output in the front direction of the micro-light emitting element.

[Other expressions of the present invention]

The present invention can also be expressed as follows. That is, an image display element according to one aspect of the present invention has: a drive circuit substrate including a drive circuit for supplying current to the micro-light emitting element and causing it to emit light; The element and the microlens on the light emitting surface of the micro-light emitting element and the partition wall arranged around the microlens, and the side of the partition wall facing the microlens can be arranged in a direction relative to the light emitting direction An image display element with a reflective surface that is inclined in an open manner and reflects light.

In addition, according to the image display element according to one aspect of the present invention, the micro-light-emitting element may also include a micro-LED comprising a compound semiconductor crystal and a wavelength conversion unit that down-converts the wavelength of the excitation light emitted by the micro-LED, and the micro-LED The light exit surface is the upper surface of the wavelength conversion part.

In addition, according to the image display device according to one aspect of the present invention, the micro-light-emitting device may include a micro-LED including a compound semiconductor crystal and a transparent portion arranged on the micro-LED, and the light-emitting surface of the micro-LED is the upper surface of the transparent part.

In addition, according to the image display element in one aspect of the present invention, the micro-light emitting element may be a quantum dot LED that emits light by passing electricity to the quantum dot layer.

In addition, according to the image display element in one aspect of the present invention, the micro-light-emitting element may also be an organic LED.

In addition, an image display element according to an aspect of the present invention has: a driving circuit substrate including a driving circuit for supplying current to the micro-light-emitting element and causing it to emit light; the micro LEDs arranged in an array on the driving circuit substrate and a wavelength conversion part that down-converts the wavelength of the excitation light emitted by the micro LED, the wavelength conversion part is formed in a hemispherical shape, and the side of the partition wall facing the wavelength conversion part can be opened relative to the light emission direction An image display element with a reflective surface that is inclined in a manner that reflects light.

In addition, according to the image display device according to one aspect of the present invention, a dielectric multilayer film that reflects the excitation light and transmits the down-converted light may be disposed on the surface of the microlens.

In addition, according to the image display element of one aspect of the present invention, the microlens may also include a filter material that absorbs the excitation light and transmits the down-converted light.

In addition, according to the image display element according to one aspect of the present invention, the partition wall may be constituted as a part of wiring electrically connected to one electrode of the micro-light-emitting element.

In addition, according to the image display element of an aspect of the present invention, the side wall of the wavelength conversion portion may also be inclined with respect to the light emission direction.

In addition, according to the image display device according to one aspect of the present invention, the reflective surface may cover the periphery of the wavelength conversion portion.

In addition, according to the image display element of one aspect of the present invention, the inclination angle of the reflection surface may be 85 degrees or less.

In addition, according to the image display element of one aspect of the present invention, the height of the reflective surface may be lower than the middle height of the microlens.

In addition, according to the image display device according to one aspect of the present invention, the microlens may cover the entire light exit surface.

In addition, according to the image display element of one aspect of the present invention, the surface of the microlens is a spherical surface, and the center of the spherical surface may be located within ±1 μm from the center of the light exit surface.

[Additional notes]

The present invention is not limited to the above-mentioned embodiments, and various changes can be made within the scope shown in the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical aspects of the present invention. in range. Furthermore, new technical features can be formed by combining the technical means disclosed in the respective embodiments.

Claims (25)

1. An image display element, comprising a plurality of micro-light-emitting elements arranged in an array, characterized in that, comprising: a driving circuit substrate including a driving circuit for supplying current to a plurality of the micro-light emitting elements and causing the micro light emitting elements to emit light, The plurality of micro-light emitting elements, a plurality of microlenses in contact with the light emitting surfaces of the plurality of micro light emitting elements, a plurality of partition walls arranged in a direction parallel to the light exit surface and around the plurality of microlenses, The side of the partition wall facing the microlens is a reflective surface, and the reflective surface is inclined in an open manner relative to the light emitting direction, And the reflective surface is not in contact with the surface of the microlens, and reflects the light emitted from the microlens in a direction along the front direction of the micro-light-emitting element, At least a portion of the partition wall is at the same height as the curved surface of the microlens in the light emission direction. 2. The image display element according to claim 1, wherein the plurality of micro light emitting elements are a plurality of micro LEDs comprising compound semiconductor crystals. 3. The image display element according to claim 1, wherein the bottom surfaces of the plurality of micro-lenses cover the entirety of the light emitting surfaces of the plurality of micro-light-emitting elements. 4. The image display element according to claim 1, wherein the inclination angle of the reflective surface is less than 85 degrees. 5 . The image display device according to claim 1 , wherein the surface of the microlens is a spherical surface, and the center of the spherical surface is located within ±1 μm relative to the center of the light emitting surface. 6. The image display element according to claim 1, wherein the partition wall is formed in contact with a surface of the drive circuit substrate. 7. The image display element according to any one of claims 1-5, wherein the shape of the partition wall viewed from the light emitting surface side of the micro-light emitting element is a rectangle. 8. The image display element according to any one of claims 1-5, wherein the partition wall comprises a partition wall base material made of a transparent material and covers the partition wall base material and is made of a highly reflective A reflective material for the partition wall composed of a metal film. 9. The image display element according to any one of claims 1-5, characterized in that, in each of the plurality of micro-light-emitting elements, the light emitting surface of the plurality of micro-light-emitting elements is Surfaces on the opposite sides respectively have first electrodes, and among the plurality of micro-light-emitting elements, sides of the light-emitting surfaces of the plurality of micro-light-emitting elements respectively have second electrodes. 10. The image display element according to claim 9, wherein the partition wall includes a part of a wiring that conducts with the second electrode. 11. The image display element according to any one of claims 1-5, characterized in that, the plurality of micro-light-emitting elements respectively have a micro-LED comprising a compound semiconductor crystal and a device that prolongs the excitation light emitted by the micro-LED. The wavelength conversion part of the wavelength, the light emitting surface of the micro-light-emitting element is the upper surface of the wavelength conversion part. 12. The image display element according to any one of claims 1-5, wherein the plurality of micro-light-emitting elements respectively have a micro-LED comprising a compound semiconductor crystal and a transparent portion disposed on the micro-LED , the light emitting surface of the micro light emitting element is the upper surface of the transparent part. 13. The image display device according to claim 11, wherein the surface constituting the side wall of the wavelength conversion portion in a direction parallel to the light exit surface is an inclined surface that opens in the light emission direction. . 14. The image display device according to claim 12, wherein a surface constituting a side wall of the transparent portion in a direction parallel to the light emitting surface is a surface inclined so as to open in the light emitting direction. 15. The image display device according to claim 13, wherein a side wall of the wavelength converting portion in a direction parallel to the light exit surface is covered with a highly reflective metal film. 16. The image display device according to claim 14, wherein a side wall of the transparent portion in a direction parallel to the light emitting surface is covered with a highly reflective metal film. 17. The image display device according to claim 11, wherein the wavelength converting portion is arranged inside the partition wall, and the wavelength converting portion and the microlens are stacked in sequence. 18. The image display device according to claim 11, wherein the reflective surface covers the periphery of the wavelength converting portion in a direction parallel to the light exit surface. 19. The image display element according to claim 1, wherein the height of the reflective surface in the direction of the center line is lower than the height of the microlens in the direction of the center line. 20. The image display element according to claim 1, wherein the plurality of micro-light emitting elements are a plurality of quantum dot LEDs, and each of the plurality of quantum dot LEDs has a quantum dot layer comprising quantum dots and is passed through to the quantum dot layer to emit light. 21. The image display element according to claim 1, wherein the plurality of micro-light emitting elements are a plurality of organic LEDs. 22. The image display element according to claim 9, wherein the first electrode is formed in a concave shape on a side opposite to the light exit surface. 23. The image display element according to claim 11, wherein on the light exit surface emitting the light of the microlens, a plurality of light emitting diodes that reflect the excitation light and transmit the light of the extended wavelength are arranged. Dielectric multilayer film. 24. The image display element according to claim 11, wherein the microlens comprises a filter material that absorbs the excitation light and transmits light of the extended wavelength. 25. An image display element, comprising a plurality of micro-light-emitting elements arranged in an array, characterized in that it has: A driving circuit substrate including a driving circuit that supplies current to the plurality of micro-light emitting elements and makes them emit light; the plurality of micro-light emitting elements; a plurality of wavelength conversion parts stacked on each of the plurality of micro light emitting elements, and a plurality of partition walls arranged around the plurality of wavelength conversion parts in a direction parallel to the light emitting surfaces of the plurality of micro-light-emitting elements, a plurality of the wavelength conversion parts extend the wavelength of the excitation light of the plurality of micro-light-emitting elements, The wavelength conversion part is formed in a shape including a curved surface convex in a light emission direction, The side surface of the partition wall facing the wavelength conversion part is a reflective surface, and the reflective surface is inclined in such a manner as to be opened relative to the light emitting direction, And the reflective surface is not in contact with the surface of the wavelength conversion part, and reflects the light emitted from the wavelength conversion part in a direction along the front direction of the micro-light-emitting element, At least a part of the partition wall is at the same height as the curved surface of the wavelength converting portion in the light emitting direction.